"I am ready to continue the dialogue," he said, adding he would discuss missile defence with Obama at a meeting in New York next week.

Russians had raised concerns that the Bush missile system, a deterrent for Iranian long-range missiles, could be aimed at them.

Al Jazeera's Alan Fisher said: "There is concern that the US decision is a political one.

"[Critics] believe that the US took this decision because they see the Russians as very important in the next steps that they are going to take against Iran.

"Therefore, the Poles and the Czechs believe that central Europe's security is no longer that important to Barack Obama, that he would much rather build closer ties with the Kremlin.

"It makes the Poles feel yet again that the Russians have got what they want through the use of force, very strong talk and quite serious rhetoric at some points."

Donald Jensen, a Russia analyst and former arms control staffer in the US Reagan administration, told Al Jazeera that the Poles and Czechs had a right to feel aggrieved at the change of plan.

"The Obama administration has effectively hit the reset button on missile defence, in a very complicated geopolitical set of moves the reflects political concerns and their technical doubts of the system previously on the drawing board.

"It sends the message not only to Poland and the Czech Republic, but to Ukraine and Georgia, that US security guarantees no matter what is said on paper ultimately don't matter much when push comes to shove."

Czech Republic

Mirek Topolanek, a former Czech Republic prime minister whose government signed treaties with the United States to set up a US "missile shield" in Europe, said Washington's decision was "not good news" for his country.

Klaus said that relations with the US were expected to continue as normal [EPA]

"This puts us in a position wherein we are not firmly anchored in terms of partnership, security and alliance - and that's a certain threat," he said.

"The Americans are not interested in this territory as they were before."

Vaclav Klaus, the Czech president, said in Prague: "I'm 100 per cent convinced that this decision of the American government does not signal a cooling of relations between the United States and the Czech Republic."

Klaus said that relations with the US were expected to continue as normal.

"This decision of the American government did not come as a surprise," he said in Prague.

Jan Fischer, the Czech prime minister, said that Obama had told him in a phone call that the planned radar on Czech land was to be scrapped.

"The Czech Republic has acknowledged this decision," he said, adding Obama had assured him that "strategic co-operation continues - that the US still sees the Czech Republic as one of its closest allies".

Jan Tamas, an activist who had organised numerous protests, said: "It is a big victory for the Czech Republic.

"We are happy that we will be able to continue to live in our beautiful country without the presence of foreign soldiers."

Poland

Lech Walesa, the former Polish president and Solidarity leader, described the decision as "not good".

Tusk said he does not describe the decision as a defeat for Poland [AFP]

"I can see what kind of policy the Obama administration is pursuing towards this part of Europe," Walesa said.

Donald Tusk, the Polish prime minister, said Obama assured him US plans to alter the missile defence project would not hurt the security of Poland or Europe.

"I would not describe what is going on today as a defeat for Poland," Tusk told reporters, adding that Obama signaled to him that "Poland has a chance to win an exclusive position" in a new system.

Alan Fisher, Al Jazeera's correspondent in Warsaw, said parties on all sides would be disappointed that the defence shield was not going ahead.

"Poles will be angry at the timing of this decision - today is the 70th anniversary of the day the Russians came across the border and took control of the country.

"They think this is really just playing into the Russians' hands.

"I've just spoken to one analyst who said the Poles would be happy to have an American ambulance based on their soil. They see it as a way of connecting to the US, of adding a little bit extra security.

"Because anyone who lived through the Soviet Bloc still worries about the possibility of the Russians coming across the border and they believe that any kind of American presence would make the Russians think twice."

"And there will be people in Poland too that will be very happy because they feared that putting the interceptors here put Poland right on the front line."